Why do children have to be so small?

Pink teddy bear

Hizashi is an absolute dumbass. He was out on patrol after school and got in a fight. Now his nose is bleeding.
"Hey, sit still."
"It's getting in my mustache!"
"Your mustache can be cleaned. Now sit still!"
I grab his chin to keep him from moving and gently wipe the blood from under his nose.
"And if you don't quiet down, you're gonna wake Eri."
"She's dead asleep, don't worry."
I rip some toilet paper and stuff it up his bleeding nostril.
"Stupid man. Getting into a fight like that..."
I sigh and stand up, kissing his forehead.
"It's late. We should head to bed. Eri wanted to have a tea party tomorrow."
"Buuuut..."
"But what?"
"I wanted to talk to you!"
"About what?"
"Life!"
"Did you hve an energy drink or something? How can you not be tired?"
"No, I just love you!"
I turn around to the sink and put toothpaste on his toothbrush, handing it to him. His hair is still a stiff cone.
"How can you stand having your hair up like this all day? Doesn't it get heavy?"
"I guess I'm used to it."
I move him over to the bathtub and have him sit on the floor next to him, leaning his neck against the edge.
"I'll wash your hair if you brush your teeth."
I grab the showerhead and turn it on, making sure the water's not too hot or too cold. I lift his head a bit further by putting a finger under his chin, and run his hair under the water. The ungodly amounts of hairspray and gel slowly wash out, leaving his long hair soft again. He closes his eyes and brushes his teeth, like I told him to. I grab the shampoo bottle and squeeze some out into his hair, massaging it in.
"You really are a dumbass. Why'd you even sign up to go on patrol?"
"Because I wanted to! I'm an adult, I do what I want!"
"A stupid adult."
"You love me."
"And that's my only weakness."
I rinse his hair again, now free from all products. I grab his bright yellow towel and wrap his hair up.
"There. All done."
"Thank you, my love."
He speaks with the toothbrush in his mouth.
"I love you so much. I have since high school. You always care for me, even if you call me stupid and loud all the time. You fix my hair and my nose and even when I do stupid stuff you never leave. Like... like ten years ago, when you said we couldn't have a wedding... and I became so upset that I actually came after you with a knife..."
I keep drying his hair with the towel as he speaks, eyes still closed behind his yellow tinted glasses.
"It was stupid, I wasn't thinking at all. Anyone else would have broken up. But you didn't."
I sit next to him on the floor and wrap my arms around him.
"Of course I didn't. I wanted to marry you. We were gonna adopt a kid. I could never raise a child on my own. I'm terrible with kids."
"No you're not. You just pretend to be."
Hizashi puts a hand in my hair. I probably need a shower too, but I'm too tired.
"I know I'm really bad at expressing my love through words... or actions... or at all..."
I sigh.
"I couldn't leave you. Even if you stabbed me in the guts. And that probably sounds really really bad and that no one should stay with someone who stabs them but... I know you wouldn't do that. And if you did, it wouldn't be the true you. You may be loud and probably exploded my eardrums once or twice, but you don't mean harm. You're kind and caring and loving and I wouldn't want anything to happen to you."
I rest my head against his chest and close my eyes. His skin is cool against mine. He's always been colder. He's always been the colder one. He's a lot leaner than I am. Not a lot of fat or muscle. I sneak a hand under his shirt and place it over his heart. It's beating... fast.
"Are you nervous, 'Zashi?"
"I'm always nervous around you. What if you put on that scary teacher persona of yours?"
"Would you want me to do that?"
A blush rises on his cheeks.
"Maybe. But I like it when you're soft like this."
Saliva mixed with toothpaste drips down his chin.
"That's gross. Get up and spit."
I let go of him and push him up, letting him spit in the sink.
"We should really head to be-"
Something tugs at my pant leg. It's Eri, she's out of bed.
"Oh, hi princess. Did we wake you up?"
She reaches her tiny hands up and I lift her up.
"Did you have a nightmare?"
She shakes her head. She looks... ashamed.
"...did you stay up waiting for papa to come home?"
A tiny nod.
"My little princess..."
I gently kiss her forehead.
"Were you worried for him?"
Another nod. Hizashi rinses his toothbrush before turning to Eri.
"I'm fine, see?"
He removes the tissue from his nostril. It's stopped bleeding.
"It's just a little scratch, baby girl."
He lifts her up and lets her lean against his chest.
"Do you wanna sleep with us tonight, baby girl? You can wake us up in time for your tea party tomorrow. Didn't you invite Izuku's mother too? As Toshinori's date?"
Yet another nod. She looks like she's already falling asleep.
"Let's head to bed, little Eri. Do you have your teddy?"
She raises her little pink teddy bear, hugging it tightly.
"Good, and you already have your pyjamas. You're all ready for bed then."
Hizashi is so good with kids. Like he's a natural. Sometimes I really wish I was like him. He opens the door to our bedroom and places Eri in the middle of the bed. I turn on the cat shaped night light we have installed for whenever Eri wants to sleep with us. I'm already wearing my pyjamas, so I slither down under the blanket, wrapping an arm around my precious daughter.
"Don't stay up late again, okay? You need your sleep."
She's already asleep, with her little head rested against my bicep. Her teddy is pressed up under her chin. She has bags under her eyes. I hope she hasn't been losing more sleep. She deserves only happiness.